Chbistian steenstbot



July 29, 1930. c, STEENSTRUP 1,771,942

ELECTRIC FURNACE Original Filed March 51, 1926 ihvenoow Christian Steenstrup by M.%:/;, 3

His Abbome i tion of the 'sur Patented uNiTso sT TES PATENT I mnrsmirsrnmsmur, or SGHENECTADY, New Yonmassmrronqro emu. amic- 'i'ia'ic comm, a CORPORATION or new You? .mmmc rrmimci:

Original application area m n 31,- 1926, Serial m. I

s 1927, Serial nogaoauc.

. The present invention relates to electric furnaces of the vtype inwvhich the operations or treatments are-carried out in: an atmosphere of selected 'in-a'clos'ed container "which is heated by internalresisto'rs orother suitable heating means S pplied with electric current from a suitable external source. p More particularly the present invention .re-. lates to a furnace of the above-named type for carrying out the process describedin my copending application, Serial No. 98,893,'filed March 31,1926, of which this application is a division. J 2

. Briefly considered, the above-mentioned process is adapted for-unitin by'fusion at v the joints, the various parts anassembled structure, particularly a structure having parts which are located in stacked or such other assembled relation to eachpther that they maybe compressed while hot to close the joints between them. By compressing the parts to close the joints, careful preliminary fitting together of the parts is obviated while at the same time'the proper capillary spacing 1;, between the parts at thejoints'is obtained,

such spacing insuring a flow of fusing metal through the joint and a proper uniting of the parts thereby as is described in my Patent No. 1,659,550. r I More ifically the above-mentioned process inc ud'es heating such assembled structure or charge with copper or. other fusing metal applied adjacent the joints thereof in an electrically-heated furnace in which a controlled atmosphere is maintained. For this purpose a non-oxidizing gas such as hydrogen, for example, is employed and iswsupplied to the heating chamber of the furnace in regulated amounts. When hydrogen is used as the as and copperas the fusing metal, the by open not only prevents oxidaaces to be joined but also acts as a flux which facilitates the flow of the melted copper into and through the joints.

Assuming the proper-temperature of the heating and- "ressin' operations.

this invent on 3 easy 98,898. Divided and this application me m '1,

furnace, thechar'ge is permitted to remain therein until the copper melts and flo'ws chicflyor wholly by ca illary action into and through the joints. ow instead of reducmg the temperature of the furnace to a point where the copper hardens and completes the 4 joints, or; removing the charge while hot and nserting it in a .cooler, I immediately subject the hot charge to such mechanical pressure as will 'force the opposing surfaces of each jointinto firm contact, Should there bea. high spot at one joint, a yielding of the metal parts will take place at this point because of their heated and somewhat softened, condition. On the other hand, should one joint be a trifle'low, the pressure applied is sufiicient' to close the s ace. at what was the low joint and into an through which the copper will thenfr'eely flow because of its molten con ion and because of the capillary size to whic the space has been reduced.

Throughout the process the charge is subjected to the controlled'atmosphere and must be quickly pressed before it coolssufliciently'- for the fusing metal toharden. It must then be as rapidly cooled as possible while being pressed, and for commercial work the process must be practically continuous: This involves' the problem of charging and unloading the furnace while in operation as well as the simultaneous heating, pressing and cooling of. the successive charge'swithout loss of time or cooling of the charges between the It is there ore,'the ect of to provide an im roved electric furnace structure which is a apted for meeting the above requirements and which permits the process I to be carried outmore rapidly and effectively, 1 while being of simple construction and of operation. For a consideration of what is believed to be novel,'attention isenow directed to the accompanying drawing, the description thereof, and the appended claims.

Referring to the drawing, 3 indicates an pelectrically-heated furnace having a heating chamber 4 in which the work or charge is located and 5 the electrical heating elements or resistors connected to a suitable source of current in the usual way. The casing of the furnace is made of metal which is heavily lined with heat-resisting material 6. Hydrogen or other selected gas is admitted to the heating chamber preferably at or about the center by. the pipe 7 and its controlling valve, 8 indicates a suitable removchamber. If desiredpan additional amount of selected gas mayJo'e supplied to the press chamber by a pipe and valve such as are used to suppl gas to theheat-ing chamber.

In or er to move the successive charges from the heating chamber,- in which one or more charges may be contained at a given time, to the pressing chamber, an actuator is provided comprising a reciprocating member 10. It may be moved. by hand or power, depending upon the weight of the charges. As shown the member has rack teeth which mesh with a pinion 11 which is rotated by a handle or crank 12. As usual sight tubes will be provided at a number of suitable points so that the condition of the charges as well as their respective positions can be determined.

Tn order to insert the charges in the furnace an elevator 13 of any suitable construction is employed, As shown, it is of the hydraulic type and is controlled by a three way valve 14. Between the lower platen or ram of the elevator and the loweredge of the furnace is a labyrinth packing 15 containing sand or steel shot to prevent the free escape of gas. When the elevator is lowered a charge is deposited on the platen or ram after which it is moved upward to the closed position and the actuator 10 .employed to move the charge into its proper position within the heating chamber.

During the period in the cycle of operation that the seal is broken. it is desirable to slightly increase the supply of selected gas to the heating chamber to keep the burning areaat or adjacent the mouth of the open ing, thereby preventing theentrance of air to the furnace. As an aid in preventing the entry of air into and consequent danger of explosion in thefurnace, the openings in the furnace are surrounded by projecting walls indicated at 15. These walls providetubular furnace openings of sufiicient length to bring the region of union of gas and air well away from or below the interior of the furnace, as indicated in the drawing.

After the'charge has been heated to a point above the melting point of the fusing metal, the. partition 8 is raised and the charge pushed by the actuator 10 on to the lower platen of the hydraulic or other elevator or press 16 which is'or may be of the same general construction as the one above described. However, it must be capable of sufficientupward movement after closingthe furnace and be strong enough to compress the charge sufficiently to ensure complete jointing or union of the parts thereof In some cases it will be desirable to accelerate the cooling by providing artificial cooling means for one' or both, of the press' platens. This may be done by a system of: cooling pipes or passages 16 located in the platens near the face thereof and shown in dotted lines. By more quickly cooling the charge the cycle of operation in some cases can be shortened.

The stationary platen 17 of the elcvator is suitably anchored as for example by cross inemberslS and vertical rods 19, the latter being anchored at their lower ends to the .base of the hydraulic cylinder, said rods being outside of the press chamber. The-joint between the movable platen or ram and the fixed cooperating part is sealed with a labyrinthv packing 20 of the character previously described but the packing is made somewhat deeper than the other 'so as to permit'the lower platen or ram to move far enough to compress the charge.

the elevator, it is raised by admitting water to the cylinder subject to the control of valve 21 and sufiicient pressure is applied to Afterthe charge is deposited on the movable platen or ram of firmly seat one part of the charge on the other or others. While in this position, the

charge is permitted to cool sufficiently to permit the copper or other fusing metal to harden or if desired, to a greater degree, after which the platenis lowered and the charge removed. The platen or rain is then elevated charge. r

In a furnace of thischaracter having as it does two ends which are capable of being opened, it is preferable to open only one end at a time so as to prevent a direct circulation of the controlled atmosphere throughout the furnace.

From the foregoing. description it will be seen that the furnace is very simple in c011 struction and may be considered to comprisea central heating chamber 4 communicating with end chambers, the open tubular lower ends of which are closed by the elevator platens. One of the end chambers designated at 22, while practically a part of the heating chamber,

preparatory to. receiving another to take-the charges presented by the elevator assoeiated therewith, while the other end chamber-9 serves as areceiving chamber for the heated charges as well as a combined cooling and pressing chamber for the charges, the elevator associated therewith functioning along with the upper platen as a press during the cooling operation.

The delivery end chamber is separated from the heating chamber by a removable partition member which withholds the heat without preventing circulation of the gas. The suita le manner, for example, after the manner of the platens in chamber 9.

With this furnace arrangement, charges may be continuously withdrawn from the delivery end and new ones added at the receiving end without dilution or loss of gas to any appreciable extent-because the end elevators are independent of each other and may be operated alternately, and because they operate automatically to close the openings through the furnace from the receiving chamber to the heating chamber, and from the heating chamber to the delivery chamber entirely by means of the actuator 10 without being lifted. The platen surfaces are then comparatively widely separated from the :packings 15 and 20 and aretherefore well above the mouth of each furnace opening.

The elevator platens thus not only ,serve as closures for the openings in the furnace but when in place to. close said openings, also provide a portion of the flooro the furnace which'is thereby rendered continuous from one end of the furnaceto the other. 7

What I laim as new and desire to seclire by Letters Patent of the United States, is:

1. In a furnace, the combination of a casing having achambered interior, one wall of which casing adjacent?- each end is provided with an opening, a movable platen associated with-each of said openings to normally close the "same, said platens being adapted to carry a charge to and from the casing, a receiving-chamber located atone end of the casing, means connected with the casing for moving a charge therethrough from one platen to the other, means in said receiving chamber and associated with one of said plat'ensfor compressing a charge, and

a heating chamber in-the casing between said end openings.

2. In a furnace, the combination of a cas ing having a chambered interior, the bottom Eartition member may be cooled in any wallof which casingadjacent'each end is provided with an opening, a movable elevator platen associated with each of said openings to normally close the same, said platens being adapted to support a charge within the casing, means connected 'with the casing for movinga charge therethrough from one platen to the other,"means associated with one of said platens for compressing a charge in a substantially vertical direction, and a heating chamber in the casing between said-end openings. a

3. In a ing having a chambered interior, the bottom wall of which casing adjacent each end is furnace, the combination of a casprovided with, an"o'pening, a movable 'eleva tor platen associated-with each-of said opcn fings to normally close the same, said platens being adapted to support a charge within a the casing, means connected with each platen for moving the same to carry a charge to and from the-casing, means connected with the casing for moving a charge theret'hrough from one platen to the other," al heating ,chamberin the casing between said end openings, a cooling chamber in said casing, means associated'with one of said platens for compressing a charge while in said cooling chamber and. a removable heat resistant partition between the last-named platen and the-heating chamber.

4. In a furnace, the combination of a casing, a heating chamber therein, said casing having openings in the bottom wall thereof adjacent opposite ends of the heating ,chamber,'ele vator means associated with, each of said openings for opening and closing the same, said means including platens for carrymg chargesto and from the casing interior through said openings, means for moving charges from one platen to the other through the heating chamber, and means associated with one'. of said platens for compressing a charge while in the casing in a'substantially vertical direction' f 5. In a furnace the combination of a casing providing a heating chamber, said casing hav-. ing an opening at each end in its bottom wall. conduit "means, for maintaining a supply of selected gas in said heating chamber, means for introducing a charge into the chamber through one of said openings, and elevator means movable upward through the other opening to compress the charge and downward to remove the charge through said opening.

6. In a furnace having a bottom wall and an opening therethrough at each end of said furnace, the pombination of a heating chamber, conduit means for maintaining therein a supply of selected gas, means for introducing a charge into said chamber through one of said openings, said means comprising a movable platen operating through said opening, a receiving chamber located. at the other end tainlng therein a of the heating chamber receive theheated tion ehargelan-d means locatedi within the receiving chamberineluding platen meansextendingthrough the other opening for compress ing thecharge andfor removing the charge ing surface and a packing through said opening. z 7., In a furnace havin a bottom wall and an opening therethrough at each end of said furnace, the combination of a heating chamber, conduit means for maintaining therein a supply -;0f.selected gas, means for introducing-a charge into said chamber through one of said openings comprising a movable platen operating through said opening, a receivlng chamber located at the other end of the heating chamber to receive the heated charge,'means located within the receiving chamber including ward through the other opening to compress /-last named platen moves andsaid platens beplaten means movable upthe charge and movable downward through said opening to remove the charge, and packing means for said platens. a

-8. In a furnace having awall and an opening therethrough, the combination of a heating chamber, conduit means for mainsupply of selected gas, means for introducing into the chamber at one end a charge comprising separate pieces which are to be united by fusion and a fusing metal, said means comprising a movable platen Whichoperates through the opening in the furnace, said platen being provided with a surface for supporting a charge and a pack ing forsealing the opening, said packing being in spaced relation to said surface in the direction of movement of the platen, adreceiving chamber located at theother end of -ing the pieces of the -therein' a supply of selected gas, means for introducing into the chamber through an opening at one end a charge comprising separate pieces which are to be united by fusion 1 and a fusing metal, said means comprising a movable platen which registers with the openmg .lIl the furnace, a receiving chamber located at the otherend of the heating chamber to receive the heated charge, means located within the receiving chamber for presscharge into firm contact to lnsure proper fusion thereof, saidmeans comprising a fixed platen, a second movable platen, and means for moving the last-named platen in the direction of the fixed platen to compress the charge and in the opposite direci to withdraw it with vided with an opening through which the each provided with a charge supporting for sealing the openingthrough which it moves, said packings being each in spaced relation to their respective charge supporting surfaces.

In witness whereof, I have hereunto hand this 6th day of July, 1927.

CHRISTIAN STEENSTRUP.

set my the charge from the I furnace, said receiving chamber belng prov 

